Elevator mechanism drive



1942. D. c. LARSON ELEVATOR MECHANISM DRIVE Filed Sept. 11, 1941 2 Sheets-Sheet 1 Hal 10M (W-2 L IVNVENTDR ATTORNEY Dec. 29, 1942. Q R

ELEVATOR MECHANISM DRIVE Filed Sept. 11, 1941 Z-ShetS-Sheei 2 5 G. IIIIIII Heb 31M MLM IYNVENTOR ATTORNEY Patented Dec. 29, 1942 ELEVATOR MECHANISM DRIVE David Carl Larson, Yonkers, N. Y., assignor to Otis Elevator Company, New York, N. Y., a corporation of New Jersey Application September 11, 1941, Serial No. 410,330

7 Claims.

The invention relates to elevators and especially to a drive for mechanism actuated in accordance with movement of the elevator car.

Many elevator systems are provided with mechanism actuated in accordance with the movement of the elevator car. Such mechanisms are utilized to control a variety of operations such as selecting floors at which stops are to be made, controlling slow down of the car and lighting the hall lanterns. When used to control the operation of the car, such mechanisms are usually termed selectors or floor controllers.

The object of the invention is to provide an improved drive for mechanism actuated in accordance with elevator car movement.

One feature of the invention resides in the provision of such a drive which may be economically applied to installations of any rise and car speed.

Another feature resides in a drive which provides both a positive and traction drive for a driving wheel for the mechanism actuated in accordance with car movement.

Another feature is the provision of such a drive in which a tape is formed to drive a toothed driving wheel for the mechanism actuated in accordance with car movement without undue noise or stress.

Still another feature is the provision of a drive in which a driving wheel is driven by a tape with a portion of the tape running on a cylindrical rim of the driving wheel t form a traction drive and with teeth formed on the tape to cooperate with teeth on the driving wheel to provide a positive drive.

Other features and advantages of the invention will be seen from the following description and appended claims.

In carrying out the invention according to the embodiment which will be described, the driving wheel for the mechanism actuated in accordance with car movement is provided with sprocket teeth and is driven by a tape having teethformed thereon with which the sprocket teeth mesh. The outer portions of the tape run on cylindrical portions of the driving wheel to each side of the sprocket teeth. The root diameter of the toothed portion of the wheel is slightly less than the diameter of the cylindrical portions. Thus the load is supported on the cylindrical portions of the wheel, limiting the central portion to a driving function. The teeth are formed in the tape by punching elongated apertures in the tape, each aperture being so shaped as to provide a pair of lips facing each other. These lips are bent outwardly to conform with the shape of the sprocket teeth, thereby presenting a maximum contact surface to minimize wear of the tape and sprocket teeth. The depth of the sprocket teeth is made such that the lips extend to the top of or slightly beyond the sprocket teeth, thereby facilitating the tape running on and off the sprocket.

In the drawings:

Figure 1 is a schematic representation of an elevator installation in which a tape drive embodying the invention is provided for a selector,

the tape being connected at its ends to the elevator car and counterweight;

Figure 2 is a similar arrangement but with the tape connected at its ends to the top and bottom of the elevator car,'the driving portion of the tape being provided with teeth and the remaining portion being plain tape;

Figure 3 is a side view of the driving wheel;

Figure 4 is a fragmental sectional detail of the same with the tape in place;

Figure 5 is a fragmental end view of the sam with the near rim removed;

Figure 6 is a plan View of a section of the toothed tape; and

Figure 7 i a longitudinal sectional view of the same.

Referring first to Figure l, the elevator car I 0 and counterweight H are suspended by hoisting roping 12 passing over a hoisting sheave l3 driven by a motor (not shown). A selector M provided as part of the installation comprises a travelling member [5 on a vertical screw IE to be actuated in accordance with movement of the elevator car. The screw is illustrated as driven through bevel gearing, chain and sprockets from a drive shaft l7. Secured to this shaft is a driving wheel [8 driven by a tape 20 provided with teeth for meshing with teeth on the driving wheel.

The toothed tape 20 is attached at one end to the top of the elevator car. This connection is effected through a hitch 2! connected to an operating device 22 for a slack tape switch 23 carried by the car. From this point the tape extends upwardly to and over driving sprocket I8 and thence downwardly to the counterweight to which the other end of the tape is connected. This connection is effected through a hitch 24 connected through a chain 25 and tensioning spring 26 to a bracket 21 on the counterweight. The spring is arranged on a rod 28 which extends through an aperture in the bracket and is provided with a stop nut 30 on its lower end to keep the tape from running oif the driving wheel and becoming tangled in the hatch in case the spring breaks.

In the arrangement shown in Figure 2 the toothed tape is connected to the top of the car through the slack tape switch as in the arrangement of Figure 1 and extends upwardly from the car to and over the driving sprocket for the selector. From this point the tape extends downwardly a suflicient distance to allow for travel of the car to the lower terminal. To this end of the tape is connected a plain tape 35 which continues downwardly and under anidler sheave 36 in the pit and thence upwardly where it is connected by a hitch 31 to. a chain"58 of a tension device 40 secured to the bottom of the car. The chain passes over an idler 41 on the tension device bracket 42 from whichit extends horizontally and is connected to a rod 43 extending through an arm M on the bracket t2. the arm the rod is provided with a washer and adjusting nut 45. On the rod between the arm and the washer is a compression spring &5 for maintaining tension in the tapes.

Of these two arrangements, the one shown in Figure 1 is preferred inasmuch as it saves tape and an idler wheel. However, where the'layout of the installation does not permit ready-connecting of the tape to the counterweight, as in cases where there are obstructions, an arrangement such as shown in Figure 2 may be employed.

Referring now to Figures 3, 4 and 5, the driving wheel l8 has sprocket teeth 51 formed around the middle of the periphery thereof. The teeth may be cut with a bicycle sprocket cutting hob for a twin roller chain. A rim 52 is provided on each side of the sprocket portion of the wheel. these rims preferably being detachable and being illustrated as such-centered onshoul'ders 53 and secured to the wheel as by bolts 54. The rims are formed with circumferential flanges 55 at the edges.

The tape, as shown in Figure 6-is provided with a plurality of spaced apertures 56 along the longitudinal center line of the tape into which the driving Wheel teeth extend. The apertures are wider than teeth 5|, the tape being guided on the driving wheel by flanges 55. These apertures are punched out in an H shape. After the punching operation all burrs are removed to prevent fatigue cracks and thus the breaking of the tape from this cause. The oppositely disposed lips 51 formed in the punching are then bent outwardly to form teeth 5% for meshing with the driving wheel teeth to provide a positive drive.

The portions of'the tape to each side of the apertures 56 run on the rims 52 to provide a traction drive in addition to the positive drive of the teeth. The diameter of the rims is preferably made slightly greater than the root diameter of the driving wheel teeth. Thus the load is supported on the rims of the driving wheel. In forming teeth 58, the lips 5'! are shaped to conform with the teeth of the driving wheel. This provides a large contact surface, thereby minimizing wear. Also, in forming teeth 53 the distance between the lips is made such as to provide clearance for the driving wheel teeth. Thus only one face of the sprocket teeth will be in contact with the lips and at times the teeth may not be touching the lips with the drive effected entirely by traction on the rims of the driving wheel. The teeth of the driving wheel are made short so that the lips 51 may extend Beyond a out to or beyond the top of the teeth. This prevents the teeth catching on the edges of the lips as the tape runs onto and ofi the driving wheel.

It will thus be seen that the drive is economically adapted to low rise low speed installations as well as to high rise and high speed installations. The driving action obtained is a combination positive and traction drive and has the advantages of both. An accurate reproduction of the cars movement is obtained enabling accurate setting of slow down initiating points as well as of floor level registrations. The drive is quiet as the tape is guided by the flanges on the driving Wheel and not the apertures in the tape and as the teeth formed on the tape extend out to or slightly beyond the sprocket teeth, thereby obviating sharp edges engaging the sprocket teeth and facilitating the tape teeth running onto and off the sprocket teeth. A maximum' tape life is assured as the formation of the teeth in the tape presents a maximum Wearing surface of the tape teeth on the sprocket teeth.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made'without departing from the scope thereof,

it is intended that all matter contained in the above description or shown in theaccompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an elevator installation in which mechanism is provided for actuation in accordance with movement of the elevator car; a driving wheel for said mechanism, said Wheel having teeth formed thereon and a rim on each side of the teeth; and a flexible tape connected to the car for driving said driving wheel, said tape having spaced apertures therein into which the driving wheel teeth extend, the portions of the tape at the sides of the apertures running on said rims, the diameter of said rims being greater than the root diameter of the driving Wheel teeth.

2. In an elevator installation in which mechanism is provided for actuation in accordance with movement of the elevator car; a toothed driving wheel for said mechanism; and a tape actuated in accordance with car movement for driving said driving wheel, said tape having apertures into which the driving wheel teeth extend, each aperture having lips at the ends thereof bent outwardly for engaging the face of said teeth, the height of the driving Wheel teeth being such that said lips extend at least to the top of the teeth.

3. In an elevator installation inwhich mechanism is provided for actuation in accordance with movement of the elevator car; a driving wheel for said mechanism, said wheel having teeth formed thereon and a rim on each side of the teeth; and a flexible tape connected to the car for driving said driving wheel, said tape having spaced apertures therein into which said teeth extend, the portions of the tape at the sides of the apertures running on said rims, each tape aperture being formed with lips which are bent outwardly to conform with the shape of said teeth, and the height of the driving wheel teeth being such that the lips extend at least to the top thereof.

4. In an elevator installation in which mechanism is provided for actuation in accordance with movement of the elevator car; a driving wheel for said mechanism, said wheel having sprocket teeth formed thereon and a rim on each side of the teeth; and a flexible steel tape for driving said driving wheel, said tape being connected at one end to the car and extending therefrom upwardly to and over the driving wheel and having spaced apertures therein along its longitudinal central portion into which the sprocket teeth extend, said apertures being wider than the sprocket teeth, the side portions of the tape running on said rims, each tape aperture being formed with longitudinal oppositely extending lips which are bent outwardly to conform with the shape of the sprocket teeth and to provide a slight clearance for the sprocket teeth, and the height of the sprocket teeth being such that the lips extend at least to the top of the sprocket teeth.

5. In an elevator installation in which mechanism is provided for actuation in accordance with movement of the elevator car; a driving wheel for said mechanism, said wheel having sprocket teeth formed thereon and a rim on each side v of the teeth; and a flexible steel tape for driving said driving wheel, said tape being connected at one end to the car and extending therefrom upwardly to and over the driving wheel and having spaced apertures therein along its longitudinal i central portion into which the sprocket teeth extend, said apertures being wider than the sprocket teeth, the side portions of the tape running on said rims, said rims being provided with flanges for guiding the tape, the root diameter of the sprocket teeth being slightly less than the diameter of said rims, each tape aperture being formed with longitudinal oppositely extending lips which are bent outwardly to conform with the shape of the sprocket teeth and to provide a slight clearance for the sprocket teeth, and the height of the sprocket teeth being such that the lips extend at least to the top of the sprocket teeth.

6. In an elevator installation in which an elevator car and its counterweight are suspended by hoisting roping extending over a hoisting sheave and in which mechanism is provided for actuation in accordance with car movement; a

driving wheel for said mechanism, said wheel having sprocket teeth formed thereon and a rim portion on each side of the teeth; and a flexible steel tape for driving said driving wheel, said tape being connected at one end to the car and extending therefrom upwardly to and over the driving wheel, said tape having spaced apertures therein along its longitudinal central portion into which the sprocket teeth extend, said apertures being wider than the sprocket teeth, the rim portions of the driving wheel being provided with flanges for guiding the tape, the side portions of the tape engaging the rim portions of the driving wheel in traction relation, the diameter of the rim portions of the driving wheel being slightly greater than the root diameter of the driving wheel teeth, each tape aperture being formed with longitudinal oppositely extending lips which are bent outwardly to conform with the shape of the sprocket teeth with the distance between the lips of each aperture slightly greater than the thickness of the sprocket teeth, and the height of the sprocket teeth being such that the lips extend at least to the top of the sprocket teeth.

'7. In an elevator installation in which mechanism is provided for actuation in accordance with movement. of the elevator car; a driving wheel for said mechanism, said wheel having teeth formed thereon; and a flexible steel tape for driving said driving Wheel, said tape being connected at one end to the car and extending therefrom upwardly to and over the driving wheel, thence downwardly and around a tensioning wheel at the bottom of the hatchway and thence back up to the car to which the other end of the tape is connected, a portion of the tape including at least that part which engages the driving wheel during movement of the car in the hatchway having spaced apertures into which the driving wheel teeth extend, the remaining portion being plain tape.

' DAVID CARL LARSON. 

